Heavy vehicle battery pack with improved cooling scheme

Abstract

A battery pack includes a plurality of multi-cell battery modules mounted within a casing. At least one fan is mounted in an intermediate position within the casing such that airflow to the fan passes over some of the battery modules, and airflow downstream of the fan passes over others of the battery modules. In one embodiment, a fan flow direction is periodically reversed. An electronic driveline for a vehicle, including the battery pack, and a method of cooling a battery pack are also disclosed and claimed.

1 . A battery pack comprising:
 a plurality of battery modules mounted within a casing; and   at least one fan mounted at a position within said casing such that airflow to said fan passes over some of said battery modules, and airflow downstream of said fan passes over others of said battery modules.   
     
     
         2 . The battery pack as set forth in  claim 1 , wherein said at least one fan is a reversible fan such that said fan pulls air in a first direction for a first period of time, and then reverses flow and pulls air in an opposed direction for a second period of time. 
     
     
         3 . The battery pack as set forth in  claim 2 , wherein said at least one fan is positioned to be in a center of said battery modules. 
     
     
         4 . The battery pack as set forth in  claim 2 , wherein there are a plurality of said fans mounted between said battery modules. 
     
     
         5 . The battery pack as set forth in  claim 2 , wherein said first and second periods of time are chosen to be less than a cell thermal time constant of the battery modules. 
     
     
         6 . The battery pack as set forth in  claim 2 , wherein said first and second periods of time are selected to be less than one minute. 
     
     
         7 . An electronic driveline for a vehicle comprising:
 at least one electric motor, said at least one electric motor drawing power from a battery pack; and   said battery pack including a plurality of battery modules mounted within a casing, at least one fan mounted in a position within said casing such that airflow to said fan passes over some of said battery modules, and airflow downstream of said fan passes over others of said battery modules.   
     
     
         8 . The electronic driveline as set forth in  claim 7 , wherein said at least one fan is a reversible fan such that said fan pulls air in a first direction for a first period of time, and then reverses flow and pulls air in an opposed direction for a second period of time. 
     
     
         9 . The electronic driveline as set forth in  claim 8 , wherein said at least one fan is positioned to be in a center of said battery modules. 
     
     
         10 . The electronic driveline as set forth in  claim 8 , wherein there are a plurality of said fans mounted between said battery modules. 
     
     
         11 . The electronic driveline as set forth in  claim 8 , wherein said first and second periods of time are chosen to be less than a cell thermal time constant of the battery modules. 
     
     
         12 . The electronic driveline as set forth in  claim 8 , wherein said first and second periods of time are selected to be less than one minute. 
     
     
         13 . A method of cooling a battery pack, said battery pack including a plurality of battery modules, and a fan mounted at a position such that said fan pulls air in a first direction, and through said fan and delivers the air downstream of said fan, it will pass over a first plurality of said battery modules on its way to said fan, and pass over a second plurality of battery modules downstream of said fan; and
 periodically reversing the flow direction of said fan such that said first and second pluralities switch over time.   
     
     
         14 . The method as set forth in  claim 13 , wherein periods of time for fan reversal are selected to be less than one minute. 
     
     
         15 . The method as set forth in  claim 14 , wherein said periods of time are selected to be less than thirty seconds.